Adjustments vs. maniacs

Well, they aren't really maniacs, since they're not aggresive preflop, but I don't know how to call them. I'm talking about the 90/0/2~2.5 villains.
You could name it variance, but I don't think it is. If I'm playing some weak-tight table, I'm winning, if I play some high players/flop table where there's most of the time one or more maniacs present, I'm losing.
I'm down 200BB, my pt-stats are near perfect, so I think I need to play different against those opponents.

What kind of adjustements do I need to make?
openlimp/limp drawing hands like JTs and small pockets, since there is no fold equity?
limp some more marginal hands and hope to catch something?
stop c-betting?
...?

It's really hard for me to play postflop. C-betting seems to be loss-making.
I can't put them on any range at all. They can bet the most crazy hands, give you no respect for your previous actions, call you down with anything,...
Valuebet more loose I thought, but then I slow down if they play back at me, wich sometimes is good, sometimes bad.
Some of my losses are properbly by tilting, but I try to keep playing normal, but it's not really working so it seems...

Try to be in position at the table. Playing these opponnts out of position is really hard as a beginner because it's hard to judge when you can calldown marginal hands.

The easiest way is to post hand where you played against them. (Especially hands where you have no good or no made hand.)

I assume that you play SH and by the silver charts. When in position you can raise nearly all hand that are listed in the open raising chart if they limp (only if just them). Just take 1-2 better hands to raise them. So if they limp in front of you and the ORC tells you to raise A5s in MP3 then you isolate them with A6s. (If you have a less showdownhand for example Q9s in CO then you raise QJs against them etc..)

Play your toppairs aggressive out of position and play valuelines with more marigal hands in position. Don't fold any pairs if the turn or river doesn't complete draws. (These are hints wih can be undrstood completly wrong so better posts hands.)

In multiway pots you can limp/call hand which needs good implied odds (suited connectors, even offsuited connectors, smallpair which are to worse to raise them).

If you think that you start tilting then stop playing even if you are behind!